Perhaps it's because you do not expect to gain with the money you take to Vegas, hence treat it and the invest money differently. On the other hand, the most I have lost in Vegas was $10 at a slot machine many years ago, and I did not get any enjoyment out of that.
I like active investing because the results are not completely driven by randomness but also by how one acts. And overcoming greed and fear is not as easy as it seems.
About making a bit of money on the side, it looks like people may not realize that options and other side bets can be used in a conservative and defensive manner, and not with a goal to score big. An example was discussed in the market timing thread started by LOL, where a holding of a market index ETF is used in conjunction with a deep-in-the-money call option to secure a 4% to 5% annual return that is protected and isolated from market swings. That is unless the market has a big drop of another 20%. In my view, it has a better return than CD, and the additional risk is small and worth it.
When I try to make a bit of extra money with side bets, the intention is not to make a few hundreds or $K net each week. When the market goes down, it is impossible to make money unless you are net short of equities. As I am still 60% in stock, the side bets are to make use of market short-term swings to hedge the long-term holdings, to reduce the loss.
If the market crashes, and I end up losing $150K net using these moves, compared to $200K if I do nothing, then I consider myself successful. Posters who read LOL's thread understand this.